Sorry, this may be a fairly elementary question, but what type of transmission fluid should I use in my 4-speed hydramatic? Thanks for your help.

 

Dexron most likely. Most people agree that all GM transmissions use type Dexron and Fords use type F but to be honest a transmission will use either type it is just best to not MIX them. So, probably the previous owner used Dexron so you should. If you are going to flush it out completely change the filter and fill with new stuff you could probably use whichever type you want. I understand there is a friction coefficient difference between the two, supposedly type F has a higher one.

 

As always, thanks for the help. I'm figuring out the "old car" thing bit by bit - just want to make sure I don't make any major mistakes.

 

Is it just regular Dexron or is there a certain Dexron? Also does NAPA have this or is there another place to find it?

thanks

 

As far as I know it is just regular Dexron. Napa should have it.

 

Dexron Mercron Type III or better. I think the stuff they sell now is Type V. If you rebuilt the transmission and it is dry then you can put whatever you want in it. I had alot of friends in college that would go through their TH 350 and put Type F in it instead of the B&M trickshift. It is essentially the same thing.

 

Type "F" fluid had to be used, in early Ford automatics, because of the clutch material they used.

In this case, you can use (and mix) anything that says "Dexron" on the label.

Norm

 

cool thanks

 

The original fluid specified for early hydro-matics was Type A, which can still be purchased. However, all variations of Dexron and Mercon fluids are compatible with the original TYPE A. The variations have to do with additives to improve shifting characteristics. Just don't ever make the mistake of adding any Type F to any transmission having Dexron or Mercon anything in it (or visa-versa) unless you want a nasty foamy mess and a rebuild.

 

if the transmission is still working fine and you just need to top it up leave the origonal whale oil fluid in it and top it up with dextron ,the origonal is better than any new fluid on the market .my 55 still runs the origonal and ill never change it if i can help it,i know i do transmissions for a living.